a rare blue mineral consisting of a sodium–calcium–aluminium silicate and sulphide: used as the gemstone lapis lazuli. Formula: (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2
Word origin
C19: from Medieval Latin lāzurlapis lazuli
lazurite in American English
(ˈlæzjəˌraɪt; ˈlæʒjəˌraɪt)
noun
a very rare, hard, bluish, crystalline mineral, (Na,Ca)7(Al,Si)12(O,S)24[SO4,Cl2(OH)2]2, that is the main component of lapis lazuli